Tuesday, October 23

Yeast Observation

Part of the study on Fungi, we also observed yeasts reproducing.

Materials Needed:
* 1 T. Baker's yeast
* 1 T. sugar
* 2 C. warm water
* Methylene blue
* compound microscope
* depression slide
* cover slip
* cup or glass
* medicine dropper

1) In a glass, mix yeast, sugar and warm water. Allow the mixture to sit for about 10 minutes. You are waiting for the yeast cells to grow and multiply.

2)Using the medicine dropper, place a drop of the yeast mixture into the well of a depression slide. Add 1 drop of methylene blue stain. Place a cover slip over the sample and place on the microscope stage.

3) Focus on low power. Then, move to high power. Identify a reproducing cell and the tiny bubbles of carbon dioxide given off by the cells.

Getting to know Fungi

  Black mold: magnified @ 4/0.16x
In this activity, we will grow and observe a number of different fungi which are present in our environment.

Materials Needed:
* slice of hard cheese
* slice of bread
* orange, apple or banana peel
* 3 sealable plastic sandwich bags

1) Inoculate your growing media (bread, cheese and fruit peel) by gently wiping each across a dusty surface.
2) Place each item inside individual sandwich bags. Add 2 tablespoons of water to each bag and then seal.
3) Place all 3 bags in a dark, warm location for 4 to 5 days or however long it takes to see mold growing in each item.

After 8 days, we removed the samples. Except for the cheese which we need to redo, we got these:

The orange peel

The bread
After observing the molds (color, size, smell, etc), we cut an entire colony from the orange peel and the bread and mounted it on the microscope slide.

Woooow! we were blown by what we saw. "Cool, Mom" was what Gia's first reaction. We are now officially loving our microscope and what it can do! =D

The orange peel had black molds growing on it. After several researches, we found out that it is Aspergillus Niger.

Kingdom : Fungi
Class: Eurotiomycetes
Order: Eurotiales
Family: Trichocomaceae
Genus: Arpergillus
Aspergillus Niger: magnified @10/0.25x
The bread on the other hand, had green mold with white cover on it. It is said to be Penicillium mold.

Kingdom : Fungi
Class: Eurotiomycetes
Order: Eurotiales
Family: Trichocomaceae

Penicillium magnified @ 4/0.16x

Penicillium magnified @ 10/0.25x
Results of the cheese will be posted here soon.

What an awesome day spent experimenting and researching and getting to know Fungus/Fungi!!

Monday, October 22

Practicing the Use of the Microscope

In these succeeding activities, we familiarized ourselves with our newly-arrived compound microscope. We got excited with all the possibilities and discoveries we shall experience using it.

Our first activity was to learn how to prepare a wet-mount slide and observe that slide using the microscope.

Activity 1: 
* Cut a small letter "g" from the newspaper and place it at the center of the glass slide. Newspaper works best for this activity as it is fairly thin and allows light to pass through it for easier observation on the microscope.

Drawing what we saw: top - magnification @ 4/0.16x; below - magnification @ 10/0.25x

Activity 2:

We did the same for a piece of blue thread and Gia's hair.

Blue thread mounted on a slide

@ High magnification: 10/0.25x
Hair at low magnification: 4/0.16x

Hair at high magnification: 10/0.25x

Awesome first tries, right? Can't wait for the next experiments.

Saturday, October 20

A Different kind of Birthday

Yes, a surprise birthday gift from my Mom. A ticket to Jonas Brothers concert in Manila!

A great excuse for Music Appreciation, being independent (yes, our Mom's were not with us---they were outside at the mall window shopping while waiting for us haha), and enjoying being a teenager.

My friend, Yeda, and I had a wonderful  and unforgettable night to remember. Really enjoyed singing and dancing with the Jonas Brothers.

Wednesday, September 26

Enzymes as catalysts

Experiment # 10: How enzymes work

Materials Needed:
* Two jars with lids
* diluted hydrochloric acid
* ground beef (raw)
* iodine
* crackers
* cornstarch
* dextrostik strips (to test for sugar)

1) In one jar, place diluted hydrochloric acid (muriatic acid) and a piece of ground beef.
2) In the second jar, put a piece of ground beef. Leave for 24 hours.
3) After 24-hours, compare the beef on both jars.
4) What is your explanation?

5) Chew a cracker for 30 seconds without swallowing.
6) Describe the change in flavor and explain the result.

7) Collect several teaspoons of saliva in a glass (saliva contains enzyme amylase).
8) Mix a paste of 1T. cornstarch and 1 c. of water.
9) Heat to boiling and cook for 10 min. Stir to prevent burning.
10) Put  1T. of the thick paste into each of  2 jars.
11) Add 1T. of saliva to one jar and 1T. of water to the other. Place in warm place for 1 hour.
12) Examine visually.
       * Describe any difference in appearance.
13) Perform the carbohydrate test on each for sugar.
      * Describe the result.
14) Perform  the carbohydrate test for starch on each.
      * Describe the result.

Photo above:
Clockwise: Jars of meat after 24 hrs; jars of meat before putting muriatic acid on one jar; water jar tested for starch; water jar tested for sugar; saliva jar tested for starch; saliva jar tested for sugar.

* Beef with the acid rapidly decomposed.
* Jar with saliva and corstarch appears clearer than the jar with water. It has sugar but does not show starch.
*Jar with water and cornstarch has no sugar but has starch.
* That enzyme amylase in saliva turns starch in food to sugar while being chewed. That is why the crackers tasted sweeter.
* Digestion breaks down proteins into its component amino acids.

Monday, September 24

Organic Compound # 2

Experiment # 9 Testing for Protein

Materials Needed:
* Protein chemical indicator (see below for details)
* Flour
* cheesecloth
* bouillon
* Dextrostik strips  or Cinitest (to test sugar)
* Iodine (to test carbohydrates)
* a variety of food

Chemical Indicator : a mixture of household ammonia with a few drops of 3% copper sulfate solution

1) Add some chemical indicator mixture to milk. What color do you observed?
L-carbo test; R-protein (#4,5)
2) Dissolve a bouillon cube in hot water and test with protein chemical indicator. What did you observe?
3) Obtain a cup of flour and mix with water to form a stiff paste. Knead for about 10 minutes, put into a cheesecloth and continue kneading under water. Continue rinsing until the water becomes milky.
4) Test the water for carbohydrates. What were your results?
5) Test the water for protein. What were your results?
6) Test a portion of the residue in the cheesecloth for carbohydrate. What were your results?
7) Test the residue for protein. What were your results?
8) Discuss results in steps 4, 5, 6 and 7.
9) Try various foods to see if they contain protein.
10) Write a summary of your results of this experiment.
Top: R- meat tested for protein; Below: L-residue tested, R- fruits tested
* Soluble starch from flour paste dissolves in water
* Insoluble residue left in the cheesecloth is protein
* Meat has protein
* Fruits tested do not have protein

Sunday, September 23

Organic Compounds #1

Experiment #8 : Testing for Sugar and Starch

Materials Needed:
* Powdered Starch
* Beakers or tumblers
* several fruits and vegetables
* Dextrostik or Clinitest (to test sugar)
* Iodine
* Sugar (Karo syrup)

1) Put a teaspoonful of starch in one beaker of water and a teaspoonful of sugar in a second beaker of water. Stir both solutions.
2) Test for starch with Iodine and sugar with Clinitest tablets or Destrostik strips.
3) Test several fruits and vegetables for starch and sugar.
L-R: Sugar; starch

Testing for Starch L-R: potato, apple, pineapple, carrots

Testing for Sugar L-R: apple, pineapple, carrots, potato

* The beaker with starch turned blue.
* The strip turned green when dipped in the beaker with sugar.
* Potato, carrots, apple turned blue when tested with iodine. Pineapple had no reaction.
* Potato and apple showed changed color on their respective strips. While carrots and pineapple did not.